Patent US4087130A successfully refreshed from Google Patents.
US4087130A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the gasification of coal in situ
Assignee: Occidental Petroleum Corp
•
Filing: 1977-04-14
•
Granted: 1978-05-02
•
Expires: 1997-04-14
Abstract
Abstract Process for the gasification of coal in situ comprising driving shafts or tunnels into a coal seam, injecting air into the bore holes to ignite and burn the coal to raise its temperature ceasing the flow of air when the coal is hot enough to support the endothermic water gas reaction, and injecting steam into the hot coal formation, such steam preferably being preheated by the flue gases taken from the same end of the bore holes where the air was injected, and recovering product gases, including carbon monoxide and hydrogen, and also product oil, exiting the tunnel at the other end of the bore holes. When the temperature of the coal drops during injection of steam to a level which will just permit combustion, the steam flow is stopped, and the cycle is repeated by air injection and flue gas removal at the front end of the bore holes, and through the tunnel connected therewith. This cyclic process is repeated until the entire mass of coal within the area encompassed by the bore holes is exhausted.
Inventors
- 👤 Donald E. Garrett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:36
CPC Classifications
E; E21; E21B; E21B43/00; E21B43/295; E21B43/16; E21B43/24; E21B43/243; Y; Y10; Y10S; Y10S48/00; Y10S48/06
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
160 words
A process for the in situ gasification of coal which comprises injecting a gaseous source of oxygen into a coal formation adjacent one end of said coal formation, and burning a portion of said coal to raise its temperature sufficiently to support the water gas reaction, removing flue gas from said coal formation adjacent said one end thereof during said burning of said coal and injecting steam into said heated portion of said coal formation adjacent said one end of said formation, to convert said heated coal to a water gas product, removing said product gas at another end of said coal formation, thereby minimizing mixing of flue gas and product gas, said injection of said gaseous source of oxygen and said injection of steam being carried out in a cyclic manner, and continuing said combustion and gasification by said cyclic introducing of said gaseous source of oxygen and said steam into adjacent heated progressive portions of said coal formation.
Claim 2
Dependent Claim
160 words
A process for the in situ gasification of coal which comprises injecting a gaseous source of oxygen into a coal formation adjacent one end of said coal formation, and burning a portion of said coal to raise its temperature sufficiently to support the water gas reaction, removing flue gas from said coal formation adjacent said one end thereof during said burning of said coal and injecting steam into said heated portion of said coal formation adjacent said one end of said formation, to convert said heated coal to a water gas product, removing said product gas at another end of said coal formation, thereby minimizing mixing of flue gas and product gas, said injection of said gaseous source of oxygen and said injection of steam being carried out in a cyclic manner, and continuing said combustion and gasification by said cyclic introducing of said gaseous source of oxygen and said steam into adjacent heated progressive portions of said coal formation.
Claim 3
Dependent Claim
39 words
The process as defined in claim 1, wherein the locations of said injection of said gaseous source of oxygen and of said steam into said coal formation are progressively moved into said adjacent heated portions of said coal formation.
Claim 4
Dependent Claim
196 words
A process for the in situ gasification of coal which comprises injecting a gaseous source of oxygen through an inlet into a coal formation adjacent one end of said coal formation, and burning a portion of said coal to raise its temperature sufficiently to support the water gas reaction, removing flue gas from said coal formation adjacent said one end thereof during said burning of said coal, stopping the flow of said gaseous source of oxygen, injecting steam through an inlet into said heated portion of said coal formation adjacent said one end of said formation, to convert said heated coal to a water gas product, removing said product gas at another end of said coal formation remote from said one end of said coal formation, thereby minimizing mixing of flue gas and product gas, and substantially segregating flue gas from product gas, and when the temperature of said heated portion of said coal formation has dropped to a level which will just permit combustion, stopping the flow of said steam, and repeating the aforesaid cycle of reintroducing said gaseous source of oxygen and said steam alternately into adjacent heated progressive portions of said coal formation.
Claim 5
Dependent Claim
196 words
A process for the in situ gasification of coal which comprises injecting a gaseous source of oxygen through an inlet into a coal formation adjacent one end of said coal formation, and burning a portion of said coal to raise its temperature sufficiently to support the water gas reaction, removing flue gas from said coal formation adjacent said one end thereof during said burning of said coal, stopping the flow of said gaseous source of oxygen, injecting steam through an inlet into said heated portion of said coal formation adjacent said one end of said formation, to convert said heated coal to a water gas product, removing said product gas at another end of said coal formation remote from said one end of said coal formation, thereby minimizing mixing of flue gas and product gas, and substantially segregating flue gas from product gas, and when the temperature of said heated portion of said coal formation has dropped to a level which will just permit combustion, stopping the flow of said steam, and repeating the aforesaid cycle of reintroducing said gaseous source of oxygen and said steam alternately into adjacent heated progressive portions of said coal formation.
Claim 6
Dependent Claim
53 words
The process as defined in claim 3, employing an injection pipe for said gaseous source of oxygen and an injection pipe for said steam, and wherein said injection pipes are progressively moved into said adjacent heated portions of said coal formations to minimize back mixing of said flue gas and said product gas.
Claim 7
Dependent Claim
78 words
The process as defined in claim 3, including a plurality of said coal formations, and said in situ gasification of each of said coal formations being carried out by alternate injection of said gaseous source of oxygen and said steam into each of said coal formations as aforesaid, and including collecting said product gas in a manifold connected to said another end of each of said coal formations opposite the air and steam inlet ends to said formations.
Claim 8
Dependent Claim
78 words
The process as defined in claim 4, including a plurality of said coal formations, and said in situ gasification of each of said coal formations being carried out by alternate injection of said gaseous source of oxygen and said steam into each of said coal formations as aforesaid, and including collecting said product gas in a manifold connected to said another end of each of said coal formations opposite the air and steam inlet ends of said formations.
Claim 9
Dependent Claim
15 words
The process as defined in claim 3, wherein said gaseous source of oxygen is air.
Claim 10
Dependent Claim
15 words
The process as defined in claim 6, wherein said gaseous source of oxygen is air.
Claim 11
Dependent Claim
88 words
The process as defined in claim 5, including bore holes adjacent and passing through each of said coal formations, said gaseous source of oxygen and said steam being alternately injected into each of said bore holes from one end of said bore holes adjacent one end of said coal formations, progressively to the opposite end of said bore holes adjacent said another end of said coal formations, and wherein said manifold is connected to said opposite ends of each of said bore holes for collecting said product gas.
Claim 12
Dependent Claim
68 words
The process as defined in claim 9, employing an injection pipe for said gaseous source of oxygen and an injection pipe for said steam, and wherein said injection pipes are progressively moved into said bore holes adjacent progressively heated portions of said coal formations to minimize back mixing of said flue gas and said product gas, from one end of said bore holes to the opposite ends thereof.
Claim 13
Dependent Claim
27 words
The process as defined in claim 10, including a second manifold connected to said one end of each of said bore holes for collecting said flue gas.
Claim 14
Dependent Claim
15 words
The process as defined in claim 11, wherein said gaseous source of oxygen is air.
Claim 15
Dependent Claim
32 words
The process as defined in claim 3, wherein said hot product gas is passed in indirect heat exchange relation with said gaseous source of oxygen and with said steam, for preheating same.
Claim 16
Dependent Claim
32 words
The process as defined in claim 3, wherein said hot flue gas is passed in indirect heat exchange relation with said gaseous source of oxygen and with said steam, for preheating same.
Claim 17
Dependent Claim
33 words
The process as defined in claim 7, wherein said hot product gas and said hot flue gas are passed in indirect heat exchange relation with said air and said steam for preheating same.
Claim 18
Dependent Claim
33 words
The process as defined in claim 12, wherein said hot product gas and said hot flue gas are passed in indirect heat exchange relation with said air and said steam for preheating same.
Claim 19
Dependent Claim
20 words
The process as defined in claim 3, wherein tailings are injected into the burnt out coal formation for roof support.
Claim 20
Dependent Claim
32 words
The process as defined in claim 12, wherein tailings are progressively injected into each of said coal formations adjacent said bore holes, as said coal formations are burnt out, for roof support.
Claim 21
Dependent Claim
130 words
The process as defined in claim 3, including blasting a coal body and forming a plurality of said coal formations, said coal formations being porous, said in situ gasification of each of said coal formations being carried out by alternate injection of said gaseous source of oxygen and said steam from adjacent pipe inlets into the top of each of said coal formations, said pipe inlets being progressively moved downward into each of said coal formations during combustion and gasification of said coal, removing said flue gas from an outlet pipe at the top of each of said coal formations adjacent to said pipe inlets, and including collecting said product gas in a manifold connected to the lower end of each of said coal formations remote from said inlet pipes.
Claim 22
Dependent Claim
15 words
The process as defined in claim 19, wherein said gaseous source of oxygen is air.
Claim 23
Dependent Claim
177 words
A process for the in situ gasification of coal which comprises forming substantially parallel access tunnels in a coal formation, forming a plurality of bore holes between adjacent parallel tunnels, the opposite ends of said bore holes communicating with said tunnels, providing a first manifold in one of said tunnels, one end of each of said bore holes connected to said first manifold, providing a second manifold in another adjacent one of said tunnels, the opposite ends of each of said bore holes connected to said second manifold, injecting alternately a gaseous source of oxygen and steam through said first manifold into one end of each of said bore holes to burn and gasify the coal in said formation adjacent each of said bore holes, removing flue gas from said one end of each of said bore holes but separated from said gaseous source of oxygen and said steam, and removing product gas exiting from the opposite end of each of said bore holes and through said second manifold, thereby substantially segregating flue gas from product gas.
Claim 24
Dependent Claim
177 words
A process for the in situ gasification of coal which comprises forming substantially parallel access tunnels in a coal formation, forming a plurality of bore holes between adjacent parallel tunnels, the opposite ends of said bore holes communicating with said tunnels, providing a first manifold in one of said tunnels, one end of each of said bore holes connected to said first manifold, providing a second manifold in another adjacent one of said tunnels, the opposite ends of each of said bore holes connected to said second manifold, injecting alternately a gaseous source of oxygen and steam through said first manifold into one end of each of said bore holes to burn and gasify the coal in said formation adjacent each of said bore holes, removing flue gas from said one end of each of said bore holes but separated from said gaseous source of oxygen and said steam, and removing product gas exiting from the opposite end of each of said bore holes and through said second manifold, thereby substantially segregating flue gas from product gas.
Claim 25
Dependent Claim
149 words
The process as defined in claim 21, wherein said gaseous source of oxygen is air and said air is injected into said one end of each of said bore holes for a period to burn a portion of the adjacent coal formation to raise its temperature sufficiently to support the water gas reaction, and said air injection is stopped, and then said steam is injected into said one end of each of said bore holes and into said heated portion of said coal formation to convert said heated coal to a water gas product including oil, said period of steam injection taking place until said heated portion of said coal formation has dropped in temperature to a level which will just permit combustion, and said cycle is repeated progressively from said one end of said bore hole to the opposite ends thereof, until said coal formation is substantially exhausted.
Claim 26
Dependent Claim
65 words
The process as defined in claim 22, employing an injection pipe for said air and an injection pipe for said steam, said injection pipes being progressively moved through said bore holes into adjacent progressively heated portions of said coal formation from said one end of said bore holes to the opposite end thereof, to minimize back mixing of said flue gas and said product gas.
Claim 27
Dependent Claim
34 words
The process as defined in claim 23, and wherein said hot product gas and said hot flue gas are passed in indirect heat exchange relation with said air and said steam for preheating same.
Claim 28
Dependent Claim
30 words
The process as defined in claim 23, wherein tailings are progressively injected into said coal formation adjacent said bore holes, as said coal formation is burnt out, for roof support.
Claim 29
Dependent Claim
165 words
A process for the in situ gasification of coal which comprises injecting a gaseous source of oxygen into a coal formation adjacent one end of said coal formation, and burning a portion of said coal to raise its temperature sufficiently to support the water gas reaction, removing flue gas from said coal formation adjacent said one end thereof during said burning of said coal simultaneously with injection of said gaseous source of oxygen, injecting steam into said heated portion of said coal formation adjacent said one end of said formation, to convert said heated coal to a water gas product, and removing product gas from said coal formation at another end thereof simultaneously with said steam injection, said injection of said gaseous source of oxygen and said injection of steam being carried out in a cyclic manner, and continuing said combustion and gasification by said cyclic introducing of said gaseous source of oxygen and said steam into adjacent heated progressive portions of said coal formation.
Claim 30
Dependent Claim
165 words
A process for the in situ gasification of coal which comprises injecting a gaseous source of oxygen into a coal formation adjacent one end of said coal formation, and burning a portion of said coal to raise its temperature sufficiently to support the water gas reaction, removing flue gas from said coal formation adjacent said one end thereof during said burning of said coal simultaneously with injection of said gaseous source of oxygen, injecting steam into said heated portion of said coal formation adjacent said one end of said formation, to convert said heated coal to a water gas product, and removing product gas from said coal formation at another end thereof simultaneously with said steam injection, said injection of said gaseous source of oxygen and said injection of steam being carried out in a cyclic manner, and continuing said combustion and gasification by said cyclic introducing of said gaseous source of oxygen and said steam into adjacent heated progressive portions of said coal formation.
Claim 31
Dependent Claim
18 words
The process as defined in claim 3, employing controlled roof caving following burning out of said coal formation.
Claim 32
Dependent Claim
18 words
The process as defined in claim 6, employing controlled roof caving following burning out of said coal formation.
Claim 33
Dependent Claim
37 words
The process as defined in claim 6, wherein said gaseous source of oxygen and said steam are alternately injected into each of said coal formations at a time for successively gasifying said plurality of said coal formations.
Claim 34
Dependent Claim
42 words
The process as defined in claim 21, wherein said gaseous source of oxygen and said steam are alternately injected into each of said bore holes at a time for successively gasifying the coal formation around each of said plurality of bore holes.
Claim 35
Dependent Claim
31 words
The process as defined in claim 6, wherein said gaseous source of oxygen and said steam are alternately injected simultaneously into two or more of said plurality of said coal formations.
Claim 36
Dependent Claim
46 words
The process as defined in claim 21, wherein said gaseous source of oxygen and said steam are alternately injected simultaneously into two or more of said plurality of said bore holes, for simultaneously burning and gasifying the coal formations adjacent said two or more bore holes.
Claim 37
Dependent Claim
26 words
The process as defined in claim 19, wherein said alternate injection of said gaseous source of oxygen and said steam flow are in a vertical path.
Claim 38
Dependent Claim
131 words
The process as defined in claim 3, including blasting a coal body and forming a plurality of said coal formations, said coal formations being porous, said in situ gasification of each of said coal formations being carried out by alternate injection of said gaseous source of oxygen and said steam from adjacent pipe inlets into the top of each of said coal formations, said pipe inlets being progressively moved downward into each of said coal formations during combustion and gasification of said coal, removing said flue gas from an outlet pipe at the top of each of said coal formations adjacent to said pipe inlets, and including collecting said product gas in a manifold connected to each of said coal formations below said pipe inlets and remote from said inlet pipes.
Claim 39
Dependent Claim
173 words
A process for the in situ gasification of coal which comprises injecting a gaseous source of oxygen into a coal formation adjacent one end of said coal formation, and burning a portion of said coal to raise its temperature sufficiently to support the water gas reaction, removing flue gas from said coal formation adjacent said one end thereof during said burning of said coal and injecting steam into said heated portion of said coal formation adjacent said one end of said formation, to convert said heated coal to a water gas product, removing said product gas at another end substantially opposite said one end of said coal formation, thereby minimizing mixing of flue gas and product gas, and substantially segregating flue gas from product gas, said injection of said gaseous source of oxygen and said injection of steam being carried out in a cyclic manner, and continuing said combustion and gasification by said cyclic introducing of said gaseous source of oxygen and said steam into adjacent heated progressive portions of said coal formation.
Claim 40
Dependent Claim
173 words
A process for the in situ gasification of coal which comprises injecting a gaseous source of oxygen into a coal formation adjacent one end of said coal formation, and burning a portion of said coal to raise its temperature sufficiently to support the water gas reaction, removing flue gas from said coal formation adjacent said one end thereof during said burning of said coal and injecting steam into said heated portion of said coal formation adjacent said one end of said formation, to convert said heated coal to a water gas product, removing said product gas at another end substantially opposite said one end of said coal formation, thereby minimizing mixing of flue gas and product gas, and substantially segregating flue gas from product gas, said injection of said gaseous source of oxygen and said injection of steam being carried out in a cyclic manner, and continuing said combustion and gasification by said cyclic introducing of said gaseous source of oxygen and said steam into adjacent heated progressive portions of said coal formation.
References Cited (Backward Citations)
US1913395A
Cited
US2786660A
Cited
US3017168A
Cited
US3298434A
Cited
US3358756A
Cited
US3865186A
Cited
US3809159A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-05-01 | 1981-10-31 | 1982-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-01 | 1985-10-31 | 1986-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-01 | 1989-10-31 | 1990-05-02 | $7700.00 | Window Closed / Lapsed |